Pull-out retainer for hydraulic lash adjuster



1967 I R; D. CORNELL 3,358,660

PULL-OUT RETAINER FOR HYDRAULIC LASH ADJUSTER Filed April 27, 1967 INVENTOR. 5/67/ 480 0. Gael/ELL AQQ WM arr/57 United States Patent 3,358,660 PULL-OUT RETAINER FOR HYDRAULIC LASH ADTUSTER Richard D. Cornell, Muskegon, Mich., assignor to Johnson Products, Inc, Muskegon, Mich., a corporation of Michigan Filed Apr. 27, 1967, Ser. No. 634,324 6 Claims. (Cl. 12390) ABSTRACT OF THE DISCLOSURE An hydraulic lash adjustor having a plunger-pillar unit that is releasable from the receiving body by axial pulling force on the pillar, causing diametral collapse of a retainer loop in a plane normal to the pulling force.

Background This invention relates to components of internal combustion engines, and more particularly to hydraulic lash adjustors.

Modern engines with overhead camshafts frequently employ hydraulic lash adjustors instead of hydraulic tappets. As is known, while the rocker arms used with tappets pivot on an axis intermediate their ends, the rocker arms used with lash adjustors have one end engaging and pivoting on an extended pillar or post which protrudes from the lash adjustor from the internal plunger. The cam engages the rocker arm intermediate the arm ends, and the other end of the arm engages the valve.

The lash adjustor pillar is an extension of the plunger, with the plunger being inside the hollow lash adjustor body, and the pillar extending axially from the open end of the body. The plunger is normally held in the lash adjustor body in the same way it is held in a tappet body, i.e. by a retainer snapped into a groove inside the body adjacent the open end. Of course, the retainer in a tappet is exposed and can be diametrally collapsed out of the tappet quite readily with a screw driver. However, the protruding pillar of the lash adjustor prevents ready access to the retainer, so that its removal can be very troublesome.

Summary of the invention It is an object of this invention to provide an hydraulic lash adjustor with a retainer assembly that is releasable by a simple axial pulling force on the protruding pillar portion, such causing diametral collapse of the retainer loop. Release of the retainer and removal of the plungerpillar unit from the body is simple and quick with the use of a pair of conventional pliers or the like.

The diametral retainer loop collapse is achieved with the axial pulling force because of the interfit and configuration of the retainer loop, retainer-receiving groove in one member preferably in the body, and a peripheral shoulder on the other member, preferably on the plungerpillar unit.

Other objects of this invention will become apparent from a study of the drawings and detailed description to follow.

Figure description- FIG. 1 is a side elevational, partially cutaway view of one form of the novel lash adjustor assembly, shown completely assembled;

FIG. 2 is a plan view of the structure in FIG. 1, i.e. taken on plane 11-11 of FIG. 1;

FIG. 3 is a fragmentary elevational partially cutaway view of the assembly in FIGS. 1 and 2, showing the structure being disassembled;

FIG. 4 is a plan view of the structure in FIG. 3, i.e. taken on plane IVIV of FIG. 3;

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FIG. 5 is a fragmentary, elevational, cutaway view of a second form of releasable retainer assembly;

FIG. 6 is a fragmentary, elevational, cutaway view of a third form;

FIG. 7 is a fragmentary, elevational, cutaway view of a fourth form; and

FIG. 8 is a fragmentary, elevational, cutaway view of a fifth form of releasable retainer assembly.

Description of the preferred embodiments The first embodiment of the invention illustrated in FIGS. 1 through 4 includes an hydraulic lash adjustor assembly 10 having a body 12, a plunger-pillar unit 14 received in said body, and with body 12, unit 14, and retainer loop 16 forming a novel releasable retainer assembly.

Body 12 has an elongated, generally cylindrical configuration, having an outer peripheral annular recess 20 for oil flow passage therearound when fitted within its receiving cylindrical cavity in an internal combustion engine (not shown), and having an oil flow passageway through the body shell between recess 20 and the interior of the lash adjust-or.

Fitted within the hollow body, having been inserted through the one open axial end 24 of body 12, is the combination plunger-pillar unit 14. It includes a plunger portion 30 received within the hollow body, and c0- operative with the body and suitable check valving means (not shown) of conventional type in the lower closed end of the body, to form the known cushioning, self-adjusting action. Since this check valve and cushion chamber assembly within the lash adjustor are conventional and widely known, they are not shown in detail. The significant factor regarding plunger portion 30 is its juncture with pillar portion 32 that projects from the plunger portion out the open axial end of body 12, to protrude axially therefrom to form a mount for the rocker arm (not shown), to be used therewith.

Retainer loop 16 maintains plunger 30 in the body, .and maintains integrally attached pillar 32 in a controlled relationship with respect to the body. Retainer loop 16 basically has a generally U-shaped configuration (FIG. 2) with slightly radially inwardly deformed ends, and is formed of spring steel or the like having an inherent bias radially or diametrally outwardly to cause its end portions to snap into the annular receiving groove 38 machined into the inner peripheral wall of body 12 adjacent open end 24. The resilient inherently outwardly biased retainer loop 16 can be diametrally collapsed deformed temporarily as illustrated in FIG. 4, to release it from groove 38.

The purpose of this invention is to cause retainer 16 to be diametrally collapsed in its plane transverse to the axis of the lash adjustor assembly, by the application of a pulling force axially of the plunger-pillar unit (see arrow in FIG. 3), as by gripping protruding plunger 32 with a pair of conventional pliers and pulling axially .away from body 12. This is accomplished by having a particular interfit and configuration of the retainer loop 16, body groove 38, and an annular shoulder 40 formed on the outer periphery of the plunger-pillar unit, basically at the junction of the plunger portion and pillar portion of this unit, and facing open end 24.

This annular, axially oriented shoulder 40 engages opposite portions of U-shaped retainer loop 16 while ad- 0 bled to body 12. Diametral collapse of retainer 16, is accomplished by providing groove 38, and specifically the face or edge 38' closest open body end 24 with a slope or taper from the deepest portion of groove 38 to the edge juncture with the peripheral wall portion 12a of body 12 that is between the groove and the open end of the body.

Hence, when axial pulling force is applied to pillar portion 32, axially facing annular shoulder 40 applies an axial force to retainer loop 16 toward open end 24. The interengagement of the smooth outer curved surface of loop 16 with sloped face 38' of groove 38 converts the axial thrust to a radially inwardly directed force on loop 16 to collapse it, i.e. radially retract it, against its inherent bias, to the contracted condition illustrated in FIG. 4 where it Withdraws from groove 38. Once removed from groove 38, retainer 16 allows the entire plunger-pillar unit to be axially withdrawn for disassembly of the structure. Insertion of the plunger-pillar assembly is achieved merely by positioning retainer 16 within the inner periphery of the structure after pressing the parts together in conventional fashion. With this structure therefore, removal of the retainer, and disassembly of the lash adj-ustor is very simple and quick, presenting no difiiculties as previously was encountered.

Once this basic interfitting and configuration characteristic described is understood, it will be realized that the configuration of the interfitting components may be modified somewhat without departing from the broad concept presented. Thus, plunger-pillar unit 14 may be employed with slightly differently configurated grooves and/or retainer loops as illustrated in the second, third, fourth and fifth embodiments illustrated in FIGS. 5, 6, 7, and 8 respectively.

Specifically, the second form of the assembly, 10a, illustrated in FIGv includes pillar-plunger unit 14 interfitting with body 12a having a groove 38a that has its edge portion closest opening 24a of very shallow depth but not necessarily tapered as in the most preferred form of the invention. Instead, retainer 16a has an outer axial face that is tapered or sloped so that the tapered face of loop 16a cooperates with the recessed edge of groove 38a to diametrally collapse under the radially inwardly directed force when axial pulling force is applied to unit 14.

In the third form of the structure illustrated in FIG. 6, the assembly b includes unit 14 fitted within body 12, but with the section of retainer 16b being square rather than round, as in FIGS. 1 through 4. The outer peripheral portion of loop 15b cooperates with the tapered surface of groove 38 to provide the removal action.

In the fourth form illustrated in FIG. 7, body 12 receives unit 14 but the snap-in retainer loop 160 has a cross section of a tilted rectangle, diametrally collapsible with radial stress applied by the slope base of groove 38 with the application of axial pulling force on the pillar portion of unit 14.

The form of the structure in FIG. 8 is similar to that in FIG. 5, in that body 12d has a groove with its outermost edge portion of shallow depth. The body receiving unit 14 is the same, and retainer 16 has a circular section. It will be noted that the projecting outer edge 38" protrudes radially in overlapping relation to the outer peripheral portion of retainer 16, but does not protrude beyond the center of the cross sectional circle of retainer 16, i.e., the edge engages the outer arcuately sloping surface of retainer 16 so that axial force applied to unit 14, and hence applied to retainer 16 by shoulder 40, will cause radially inwardly applied force by shoulder 38" to the curved surface of retainer 16 to diametrally collapse it sufi'lciently for removal. In other Words, the radius of the cross sectional circle of retainer 16 is greater than the off-set of groove edge 38".

It is conceivable that certain other structural variations may be made within the broadest aspects of the concept presented. For example, the shoulder may project radially inwardly on the body inner periphery, and the groove may be in unit 14. However, this would leave the retainer in the body and would be less desirable. The invention is intended to be limited only by the scope of the appended claims and the reasonably equivalent structures to those defined therein.

I claim:

1. A releasable retainer assembly in an hydraulic lash adjustor having a hollow body with an inner periphery and an open end, a plunger-pillar unit including plunger portion in said body and a support pillar portion projecting from said plunger portion out said open body end; said releasable retainer assembly having a retainer receiving groove in said body inner periphery and a radially collapsible retainer having an inherent radially outward bias normally holding it in said groove; the improvement comprising: said plungenpillar unit having a peripheral shoulder adjacent to and axially engageable with said retainer whereby said plunger portion of said unit is normally retained in said body by said retainer; and said shoulder, retainer, and groove being interfit and con-figurated in a manner that axial pulling force on said pillar portion, outwardly of said body, causes diametral collapse of said retainer by said shoulder and groove to release said plunger-pillar unit for removal from said body.

2. The releasable retainer assembly in claim 1 wherein said groove is tapered radially inwardly toward said open body end to cause diametral collapse of the retainer.

3. The releasable retainer assembly in claim 1 wherein said groove has a retainer collapsing edge axially toward said open body end.

4. The releasable retainer assembly in claim 1 wherein said retainer has a tapered surface toward said open body end.

5. The releasable retainer assembly in claim 1 wherein said retainer has an arcuate outer peripheral surface, and said groove has an edge axially toward said open body end that engages and slightly radially overlaps said arcuate outer peripheral surface.

6. A releasable retainer assembly in an hydraulic lash adjustor having a hollow body element with an inner periphery and an open end, a plunger-pillar element including plunger portion in said body element and a support pillar portion projecting from said plunger portion out said open body element end; said releasable retainer assembly having a retainer receiving groove in one of said elements, and a radially collapsible retainer having an inherent radial bias normally holding it in said groove; the other of said elements having a peripheral shoulder adjacent to and axially engageable with said retainer whereby said plunger portion is normally retained in said body by said retainer; and said shoulder, retainer, and groove being interfit and configurated in a manner that axial pulling force on said pillar portion, outwardly of said body element causes temporary diametral deformation of said retainer, against its inherent bias, by said shoulder and groove, to release said plunger-pillar element for axial removal from said body element.

References Cited UNITED STATES PATENTS 2,309,740 2/1943 Voorhies 12390 2,432,762 12/1947 Hoern 123-90 2,858,817 11/1958 Line 12390 3,151,603 10/1964 Schurnm 12390 AL LAWRENCE SMITH, Primary Examiner. 

1. A RELEASABLE RETAINER ASSEMBLY IN A HYDRAULIC LASH ADJUSTOR HAVING A HOLLOW BODY WITH AN INNER PERIPHERY AND AN OPEN END, A PLUNGER-PILLAR UNIT INCLUDING PLUNGER PORTION IN SAID BODY AND A SUPPORT PILLAR PORTION PROJECTING FROM SAID PLUNGER PORTION OUT SAID OPEN BODY END; SAID RELEASABLE RETAINER ASSEMBLY HAVING A RETAINER RECEIVING GROOVE IN SAID BODY INNER PERIPHERY AND A RADIALLY COLLAPSIBLE RETAINER HAVING AN INHERENT RADIALLY OUTWARD BIAS NORMALLY HOLDING IT IN SAID GROOVE; THE IMPROVEMENT COMPRISING: SAID PLUNGER-PILLAR UNIT HAVING A PERIPHERAL SHOULDER ADJACENT TO AND AXIALLY ENGAGEABLE WITH SAID RETAINER WHEREBY SAID PLUNGER PORTION OF SAID UNIT IS NORMALLY RETAINED IN SAID BODY BY SAID RETAINER; AND SAID SHOULDER, RETAINER, AND GROOVE BEING INTERFIT AND CONFIGURATED IN A MANNER THAT AXIAL PULLING FORCE ON SAID PILLAR PORTION, OUTWARDLY OF SAID BODY, CAUSES DIAMETRAL COLLAPSE OF SAID RETAINER BY SAID SHOULDER AND GROOVE TO RELEASE SAID PLUNGER-PILLAR UNIT FOR REMOVAL FROM SAID BODY. 